In a process of individually separating and recovering various metals that can be contained in various batteries and semiconductors, electric and electronic parts or other metallic materials, for example in order to recycle metals used or discarded in applications such as the above various batteries and the like, metal-containing solutions such as iron-containing solutions containing iron ions can be obtained by treatments of pulverizing the used metals and dissolving them in acids or like or many other treatments.
For recovery of each metal ion as a solid from the metal-containing solution that may contain various kinds of metals as metal ions, it is necessary to sequentially subject the metal-containing solution to a plurality of stages of solvent extraction or neutralization depending on the metals to be separated and further subject each solution obtained in each stage to reverse extraction, electrolysis, carbonization or other treatments, in order to separate each metal leached in the metal-containing solution.
As an example of such a method for recovering the metals, for example, when recovering the valuable metals or the like from lithium ion battery scraps, the lithium ion battery scraps in the form of powder or particle obtained through each step such as roasting, crushing and sieving as required are firstly leached with an acid and lithium, nickel, cobalt, manganese, iron, copper, aluminum or the like that can be contained therein are dissolved in an acidic solution to obtain a leached solution.
The leached solution is then subjected to a solvent extraction method to sequentially separate respective metal elements. Here, each valuable metal can be recovered by firstly recovering iron and aluminum, subsequently recovering manganese and copper, then cobalt, and then nickel, and finally leaving lithium in the aqueous phase.